2nd part: *:obligatory=yes/no

Introducing the tag *:obligatory=yes/no as a suffix for bicycle=* on shared/non-shared cycleways that are obligatory to use by cyclists on grounds of a law or by the rules of traffic. The default value for all cycle infrastructure is bicycle:obligatory=no. This way the tag does not need to be applied in countries without such laws.

In it's current form this proposal is aimed at transport mode bicycle on shared and non-shared highway=path/cycleway and cycleway=track as inherent part of a road. Usage for transport mode foot could be part of a later development of this proposal.

On separate ways the value bicycle:obligatory=yes should only be used in combination with bicycle=use_sidepath on the parallel carriageway. The tag should not be used if the roadside cycleway is the only available option because the main road is a motorway, motorroad or cycling is prohibited by a traffic_sign like .

The tag should not be used on cycleway=lane since these are always obligatory (feedback needed).

Note however that some countries have obligatory status only on cycleways with specific signals.

E.g. in France, cycles and pedestrians can go almost everywhere (they must still respect the priorities and cross roads/streets carefully), except when there are explicit traffic signs fordidding such access; however, on trunks and motorways with their standard signals, pedestrians, unmotorized bicycles or slow motorcycles, and cannot enter unless there's a specific sign authorizing them (but generally this is through a parallel designated footway or cycleway with a protecting separation, e.g. on bridges, which should be traced separately; so in France, indicating the obligatory access is only needed for other kinds of vehicles, notably heavy trucks or for transports of dangerous materials, with exceptions allowed only for local delivery or in specific hours, but not for normal transits).

Rationale

The introduction of bicycle=use_sidepath to resolve the (mis)use of bicycle=no has created a feasible option to mark the existence of an obligatory cycleway next to a highway=residential/... and solves the routing problem.

It is currently not possible to see whether a cycleway is obligatory from tags itself. Obligatory cycleways are a very political topic in Germany. From experience of tagging cycleways in Germany can be learned, that there is a need to express the difference between shared/non-shared cycleways that are obligatory to use and other "freedom of choice" cycleways.

This has been done by the (mis)use of existing tags in various ways so far.

The property obligatory is no classical access tag. It's a property of a way for a mode of transport which is orthogonal to access and road type, so it is defined as a prefix here. While it is true that every obligatory cycleway is also bicycle=designated, access is about restriction and not for reasons why somebody has to take this way instead of others.

Problems with *=designated/yes

The Lübecker Methode uses the difference of highway=cycleway/path + bicycle=designated to identify a obligatory cycleway vs. highway=cycleway/path + bicycle=yes for a "freedom of choice"-cycleway.
This has the problem that access=designated is defined as "indicates that a route has been specially designated (typically by a government) for use by a particular mode (or modes) of transport.". It does not imply obligatory access or restrictions for other mode of transport. A well-built non-obligatory cycleway has to be tagged with bicycle=yes, indicating a lesser quality of travel.

Problems with bicycle=obligatory and cycleway=obligatory

From user FKV: "Nobody is obliged to use a certain cycleway. Such a cycleway is just an alternate route for a road where bicycles are banned. It's that ban we need to map."

Countries with obligatory roadside cyclepath laws

France: since 1999 most paths should be made non-obligatory, but conversion rate is low

Poland: all

Italy: obligatory and non-obligatory

Switzerland: all

Austria: obligatory, non-obligatory possible since 2013

Tag name

In June 2014, for British cycle lanes the key mandatory was proposed, but as in U.K. all cycling facilities are optional for cyclists, the use of the term mandatory in British traffic law means forbidden for other vehicles = reserved but only optional for cyclists. [1]